Steering apparatus



IJR 15, 1947. H. v. PUTMAN ET Al. 2,419,164

STEERING APPARATUS F'led Aug. 19, 1944 5 Sheets-Sheet 1 Mrwmm ATTORN EY'April 15, 1947 H. v. PUTMAN x-:T A; 2,419,164

STEERING APPARATUS Filed Aug. 19, 1944 3 Sheets-Sheet 2 ATTORN EY April15, 1941 H. v. PUTMAN ETAL 2,419J64 STEERING APPARATUS Filed Aug. 19,1944 3 Sheets-Sheet 3 WlTN ESSES:

BY Md y ATTORNEY Patented Apr. 15, 1947 UNITED STATES PATENT FFI'CESTEERNG APPARATUS Henry V. Putman and Merrill G. Leonard,'Sharon, Pa.,assignors to Westinghouse Electric Corporation, 'East Pittsburgh, Pa., acorporation of Pennsylvania Application Augustli), 1944, Serial No.550,249

4 Claims. 1

Our invention relates to gyroscopic control apparatus and moreparticularly to gyroscopic control apparatus for submersible crafts asto torpedoes.

'The Government of the United States has been granted a certainroyalty-free license for ,governmental purposes with respect to theinvention herein described.

Gyroscopic control for steering a torpedo is well -known but with therecent first fairly extensive use of electrically propelled torpedo somespecial problems called Vfor solution.

One object of our invention is the provision of simple and reliablegyroscopic steering control apparatus for a torpedo.

Another object of our invention is the provision `of clutching means forthe drive ofagyro wheel interlocked with locking means `for the rotatingassembly which when unlocked `provides three degrees of freedom withrespect .to rotation for the `gryro wheel.

Another object of our invention is the provision for steering controlthat is .substantially yunafiected by vibration fof the torpedo.

,A still further object of your invention `is the provision of automaticmeans `responsive to the firing of a torpedo for vstopping the gyro`wheel drive motor, disengaging the gylo IWheel Vfrom the drive motor,and ,releasing .the igyrorwheel that it has three degrees of freedomYof, rotation.

The foregoing objects expressly made `are merely illustrative, .and arenot in 'the least to be taken as exhaustive statements of the objectsand advantages of Your invention. IMany other objects and advantageswill become ,more `read-- ily apparent from a ,study of the followingspecication and the .appended claims when .made in conjunction with theaccompanying drawings, in which.:

Figure 1 is .adiagrammaticshowing of the .electrical control and aschematic showing of some of the mechanical elements coacting with ythe`electric control;

Fig. 21s a view from the aft region, with certain 4parts broken away .atthe left and at the top, showing our steering control gyro;

3 is a side viewfrom the port side, of `our control gyro, the :casebeing 'broken ,away and .some .other .parts `being broken laway toillustrate some details; rand Fig. 4 is a plan -viewoi vour` controlgyro.

To gai-n a better understanding .of the :details of our invention, -a`brief general discussion `of gyroscopic steering ,of torpedoes and a4study of the operation oi the electrical equipment shown in Fig. 1 maybe helpful.

In Fig. l we show a portion ci a torpedo `in cluding the tail-cone I,the afterbody- 2, `and a portion of the main section fio-f .a torpedo.:Since the torpedo `is electrically propelled, we show a battery Bvarranged to be connected to the torpedo propulsion motor M. Thepropulsionmotor is, through shaft 4S and suitable transmission gears,coupled to vthe two propellers Pto drive them, respectively, in.opposite directions during propulsion of the torpedo. The motor 1M isalso coupled to `drive a distance gear d for operating `a drumcontroller or other suitable switches 5 for eiecting certain controlfunctions, some of which constitute no part of our invention.

The torpedo, as is well known, is providedwith horizontal rudders 6 forcontrolling the depth ci operation of the torpedo and withvertical'rudders l and .8 for controlling the course of the torpedo..Our invention is primarily concerned with 'the control of the .verticalrudders.

The vertical rudders are mechanically coupled to the armatures 9 and Inwhich are in turn actu- .ated by the solenoids El) and lll. The gyro, orrgyrostat, G, to effect proper steering of the torpedo vtoward the enemytarget, controls "the energizaticn Vof solenoids 4D and '41.

Normally during transportation, the 'rotating `assembly of ,gyro Grislocked in fixed position on the torpedo and the gyro wheel 23 is inclutching engagement with the gyro motor GM. Just `before the torpedo.is fired, the gyro wheel is brought up to .full speed by the gyro motorGM and the course for the .torpedoris selected by so positioning thecontact segments ,2S and 3i), having Athe relatively narrow spacer 3lo'f insulation between them, that the spacer 3l points in the directionrequired for the course setting selected.

Just beforeiirng the switch l I is closed Whereupon a circuit isestablished from the upper terminal `of the lbattery B through switchll, conductor l2, through the gyro motor GM, conductor 13, contacts i44of the gyro transfer switch l5 to the lower terminal of the battery.

Substantially at the same time switch 'Il is closed, the l.course forthe torpedo is set. The gyro wheel 23 attains full speed in a relativelyshort time whereupon the torpedo is fired.

r.l'heinstantthe torpedois fired the trigger lever 'I'.actuated bythedog D closes the ,switch I6 to thus establish a circuit from thepositively .energizedconductor 'I2 through switch IB, coil IJ of the.clutching mechanism 'I8 to the negatively ,energized conductor I3.

Energization of coil, or solenoid, I1 actuates the armature 1.9 towardthe right thus Amoving the lever 2B pivoted at 2| clockwise to thuscause the `clutch 22 to release its driving connection between the ,gyromotor GM and the gyro wheel. The clockwise movement oi .the lever 2l]releases the spring biased levers 24 and 25 so that they move clockwiseand counterclockwise, .respectively. .Counterclockwise movement of.lever 251eleases the .spring biased gyro `transfer switch .I5 rso `thatthis switch opens its contacts lA and hand halfl of resistor closes itscontacts 28. Opening of contacts |4 effects deenergization of both thegyro motor GM and the coil I1, both of which at this stage being nolonger needed.

Closure of contacts 28 establishes a circuit from the positive terminalthrough the actuating coil of contactor 21 and contacts 28 to thenegative terminal of the battery B. Operation of contactor 21 causes theclosure of contacts 26 to thus connect the propulsion motor M to thebattery to propel the torpedo through the water.

To eiect proper steering of the torpedo toward the target the contactsegments 29 and 30, having the relatively narrow strip of insulation 3|between them, are so positionedthat the strip 3| holds a given positionwith reference to the target. The given position nearly always meansthatthe strip 3| points toward the target; it thus indicates thedirection the torpedo is to take to arrive at, or hit, the target. Forall torpedo shots except one directly at the target the small contactroller 32 will be in Contact with either segment 29 or segment 30,depending on the direction of the target with reference to the torpedotube.

Assuming that the target is to the left of the longitudinal axis of thetorpedo as it is fired, then the small roller 32, making substantiallypoint contact, will be in contact with segment 30. This means a circuitis established from the positive terminal of the battery throughcontacts 33, potentiometer resistor 34, conductor 35, terminal contactarms 90, 9|, and 92 coupled to `rotate with the outer gimbal ring 1I) ofthe gyro, roller 32, segment 3U, actuating coil 36 of the steeringcontrol relay 31 back to the junction between the potentiometer resistorand contacts 33.

The circuit traced will cause operation of the relay 31 to close itscontacts 38. Closure of contacts 38 establishes a circuit from thepositive terminal of the battery through contacts 26 and 38, conductor33, solenoid or coil 40 for actuating the armature l0, and conductor 4|to the negative terminal of the battery,

The rudders 1 and 8 are thus deflected so as to turn, or steer, thetorpedo toward the left.

This deflection of the rudders continues until the torpedo has moved tothe left sufciently so that the roller 32 comes into contact with thestrip of `insulation 3|. When this happens the direct circuit for coil36 of the relay 31 is interrupted at the roller and it is connected inseries with relsistor 42.

Resistor 42 has a relatively high resistance value to thus decrease theenergization of coil 36 .longitudinal axis of the torpedo. In order thatthe control operation or effect of the gyro may be invariable and beimmediately ,effective in proper magnitude the potentiometer .resistoris connected to the battery when the torpedo boat arrives at the battlestation. The circuit -for the potentiometer resistor 34 may be tracedfrom the positive terminal of the battery through the contacts 33,potentiometer resistor 34, back to the negative terminal of the battery.

The actuating coil 36 is connected in series with the resistor 42 andsegment 30 across the left- 34. The actuating coil 43 is similarly inseries circuit with resistor 48 and segment 23 connected across theleft-hand half of. resistor 34. The resistance values of resistors 42and 4B are so chosen that the coils 36 and 43 and the resistors 42 and48 are at a stable temperature. The coils 36 and 43 thus, when calledupon to control the rudders, are already heated and thus produceinvariable control eiiect.

Further, the segments 29 and 30 are during transportation of the torpedoso adjusted that the roller 32 makes contact with the strip 3| only.Coils 36 and 43 are thus energized an equal relatively small amount. Theenergization is just sufficient to produce the heating effect mentionedbut insuiiicient to cause actuation of the relays 31 and 44.

It is, of course, apparent that the control effect hereinbeforediscussed is not dead beat and in consequence there is some tendency, atleast on the first approach of the torpedo to a position such thatroller 32 falls on the strip 3|, for the torpedo to move beyond therequired direction.

'As the torpedo moves beyond the desired direction the roller 32 makescontact ,with segment 23 whereupon coil 43 of relay 44 is directly andfully energized and this relay closes its contacts 45. Closure ofcontacts 45 establishes a circuit from the positive terminal of thebattery through contacts 26 and 45, conductor 46, coil or solenoid 41for actuating armature 9, to the negatively energized conductor 4|. Therudders 1 and 8 are again actuated to bring the torpedo back on thecourse.

After a few possibly rapid and possible aperiodic hunting cycles thetorpedo takes a steady substantially direct course toward the target.What hunting there is after a steady state is obtained is not great andis periodic and thus does in no way harmfully aiect the course of thetorpedo.

If the torpedo has moved beyond the target as determined by the rangesetting of the distance gear 4 without making a hit the controller 5will establish a circuit from the positive terminal of the batterythrough contacts 26, conductor 49, segment 5|), conductor 5|, actuatingcoil 52 of the spiralling relay 53, to the negative terminal of thebattery.

Operation of the spiralling relay opens the contacts 33, thusdisconnecting the gyroscopic control, and closes the contacts 54. Acircuit is thus established from the positive terminal of the batterythrough contacts 54, resistor 55, conductor 46, solenoid 41, andconductor 4| back to the negative terminal of the battery.

This energization of the solenoid 41, through armature 9 operates therudders 1 and 8 hard over to one side, and in consequence the torpedobegins to move in a spiral seeking the target it failed to hit.

In the absence of resistor 55 the torpedo might move in circles but thecharacteristics of resistor 55 are so chosen that the resistance valuekeeps rising as it becomes heated. This means that the energization ofthe solenoid 41 decreases more and more and the rudders are held in thehard-over position with less and less force. As the torpedo speed isstill not materially diminished the spiral operation of the torpedo isobtained.

If, in spite of the spiral searching of the torpedo for the target, itstill fails tomake a hit, the battery will become exhausted and thepropulsion motor will stop. Since the torpedo normally has a negativebuoyancy, it will, under these conditions, sink and thus not become amenace to shipping generally.

While We have gone into considerable detail about the steering controlsystem, the structural features of our gyro are no less important but4constitute an important contribution to the art.

As seen in Figs. 2 Vand 3, it will be noted that the gyro wheel 23 ismounted on the inner gimbal ring 6B for rotation about the spin axisfalling, as `near as manufacture can accomplish this inthe geometricaxis of the drive shaft BI for the gyro Wheel.

'I'he left-hand end of the inner gimbal ring 60, as -seen in Fig. 3, isprovided with a hollow stud 62 threaded externally and threadedinternally. Disposed within the stud beyond the internal threads, theouter race 63 of the ball bearings is positioned. To prevent any axialmovement ofthe drive shaft 4with reference to the gimbal ring 60 the nutE4, having the sleeve extension or projection 65 shown at the right endof the nut, is driven down so that the extension rmly `engages the outerball bearing race 63. The drive shaft 6l `thus has no end play towardthe left.

At the right, the gimbal ring 50 has an internally threaded opening forreceiving the external threads of the knurled generally cup shaped nut66. The base of the nut E6 is provided with an opening through thesleeve-like left end of the clutch disk, or clutch cone, 61 extends. Aroller bearing similar to the one at the left is positioned in the nut6E. A washer 58 is disposed directly to the right of the roller bearing.This washer has an annular left-hand projection engaging the outer race69 of the ball bearing and an annular right-hand projection forcentering the compression spring 'I. The compression spring Til ofsuitable design and under a selected compression firmly positions theball bearing so that shaft El has no end play in a direction toward theright.

At points directly at right angles to the spin axis the inner gimbalring 60 is journalled in the outer gimbal ring 10. These journals arealso provided with ball bearings which are rmly held against axialdisplacement as shown at the left in Fig. 2.

At points directly at right angles to both the spin axis and the axis ofrotation of the inner gimbal ring 60 on the outer gimbal ring 10, theouter gimbal ring is journalled in the frame H of the gyro mechanism.This is best shown in 2. It will be noted that the annular nut 'i2 hasan inner downwardly directed shoulder against which the outer race ofthe upper ball bearing 13 rests so as to prevent the possibility of anyupward axial movement of the control shaft 14. At the lower journal forthe gimbal ring 'I a nut 75 having an annular inner projection engagingthe outer race of the ball bearing 'IB prevents any downward axialmovement of the control shaft.

The axis of rotation of the outer gimbal ring in the frame 'Il isdisposed at right angles to the axis of rotation of the inner gimbalring 60 on the outer gimbal ring 1l? and also at right angles to thespin axis of the gyro wheel. The arrangement, design and care ofmanufacture is such that the three axes are mutually perpendicular axesintersecting at the point of the center of mass of the rotating system.This means that the gyro wheel, assuming perfect balance and assumingthe conditions of intersection for the axes mentioned are satisfied, isa solid body unconstrained with reference to rotation, since the bodycan rotate about any one, two, or all three of the axes. Such a body ifset to spin, disregarding friction turques, etc., will indefinitelymaintain .its spin axis in a given direction in space.

From the foregoing, it is vapparent that if a pointer were `to beattached to the upper Yend :of the control shaft 14 and the gyro wheelwere spinning at a relatively high speed, .any .movement of the frame Il'in uazimuth about the shaft 14 Would in nowise aifect the dispositionfof vthe pointer in space.

In practice, the control shaft T4 is mounted so as to bein a verticalposition when the torpedo is on even keel. The depth .control devices:so acontrol the travel of .the torpedo that the control shaft 14 doesremain in a substantially vertical position.

We, therefore, need merely to obtain a suitable controlling elfect fromthe position of such hypothetical pointer at the top of shaft M withreference to some point on the torpedo. This control effect we obtainfrom 'the mechanisms mounted at the top of the gylostat frame. Before wediscuss these features of our invention, we must take into account atleast two more factors.

It is manifestly impossible to obtain perfect balance of a rotatingsystem Vmerely by careful dimensioning, machining, and positioning ofthe parts. After our `gyro Wheel and the rings associated with it havebeen carefully balanced, it is necessary as an added precaution and anadded refinement that the rotating system loe rebalanced after assembly.This we accomplish by means of the balancing nut Tl disposed on theouter threads of the hollow stud 62. By'carefully shifting the `nutaxially ofthe stud, a position can be obtained for the nut on the studto make the gyro wheel unconstrained with respect Ito rotation.

An index is then placed on the extension strip 78 and on the nut, sothat the position of balance is indicated.

The other factor is one dependent on the latitude at which the torpedois lired. Suppose the torpedo were fired from a position at latitude.toward a target some distance away. Since the hypothetical pointer atthe top of the control shaft 'I4 continues to point in the samedirection in space, the torpedo, if following the direction in which thepointer points, will miss the target because the target not being atlatitude 90 `will have moved east by an amount directly dependent uponthe time it took for the torpedo to travel from latitude 90 to thelatitude of the target.

At other latitudes than 90, the discrepancy will not be as great, butnevertheless will be a function of the ratio of time to the sine of theangle `of latitude.

If a force of the right magnitude and distance from lthe center of masscan be caused to act perpendicular to the spin axis, just the rightamount of precession can be given to shaft 14 to compensate forlatitude. We use the weight 11 for this purpose.

The weight 71, after its balance position has been xed, is provided withgraduations indicating the extent to which the nut must be moved towardthe left or away from the center of mass for various degrees oflatitude.

At the upper portion of the frame H, we rotatably mount the annularmember 'lil on the projecting hollow stud 80. At the outer periphery ofthe sleeve-like extension 8|, we provide gear teeth 82 for engagementwith a Worm on shaft 83. By means of suitable shafts carrying bevelgears as shown, the transmission is carried to the shaft 84 (see Fig. 2)The shaft 84 is disposed athwart the torpedo and the ends are providedwith cou plings 85 and 86, so that the 'annular member 19 may beangularly adjusted from either side of the torpedo. The drive to.the'c'ouplings 85 and 86 may be done from the outside without thechance of any leakage into the torpedo at such points after the torpedois iired.

Mounted on the annular member 19 is the cap 81 of insulating material.This cap has an annular projection 88 to firmly hold it on the member 19so that it may rotate with member 19 when setting the course for thetorpedo. Rigiclly se cured to .the inner periphery of the cap are twosemicircular segments 29 and 30 of conducting material separated by tworelatively narrow dametrically disposed insulating strips, one of which,as 3|, being shown in Figs. 1 and 2.

Connected to the upper end of the control shaft 14 is the disc-likeconstruction 89 upon which is mounted the relatively wide and fairlyrigid strap 90. To one end of strap 90 is secured the leaf-springcontact, or current-carrying member, 9|. The other end of the strap isbent up at right angles to the plane of the strap. To this bent-up endis secured the contact strap 92 carrying the roller 32. Elements 90, 9|,92 and 32 in effect constitute the hypothetical pointer mentioned. Thisstrap 92 is disposed with the edges up and down, that is, the sidesurfaces falling in Vertical planes.

'Considerable vibration occurs on a torpedo and not to subject thecontrol to the danger of current failure at the roller 32, the strongstrap 90 and the edgewise disposition of strap 92 prevent shifting ofthe roller 32 with reference to the segments 29 and 30 so as to have anyelectric circuit open at the roller.

Vibration radially of the shaft 14 is not very prevalent, besides strap98 permits of no radial vibration of the roller 32 and strap 92 `is tooshort and too strong to permit such vibration. Our construction thusprevents current interruption at roller 32 because of vibration.

Disposed on the frame 1| is an index 93 coacting with graduations on theconical surface 9|! of the cap 81. This index 93 and the graduations onsurface 90 are visible from the outside of the torpedo through alens-like window. The disposition of the graduations is such that theyindicate with reference to the index 93 the exact angle shot that isbeing made. In other words, if the target is disposed 37 and 30 to theright of the torpedo tube, the attendants through couplings 85 or 88rotate the cap until 37 and 30 to the right of the zero graduationregister with the index. This means the insulating strip 3| is disposed37 and 30' to the right of the position of the point contact of roller32 with segment 29. Then when the torpedo is red, the steeringmechanisms willturn the torpedo until the roller contacts the strip 3|at which time the torpedo is on course.

It is manifestly important that the gyro wheel and the gimbal rings beso locked in position while the gyro wheel is to be brought up to speedthat the clutch disc El makes proper operative contact with the clutchelement |08 but that the gimbal rings 60 and 18, after release of theclutch elements 61 and |89, be free to rotate.

- The clutch actuating lever 20 is of the inverted Y-type pivoted at theends of the Y. At the crotch, the lever straddles the clutch actuatingspool-like sleeve |82. This sleeve is actuated toward the left by arelatively heavy spring |04 to normally cause rm engagement of theclutch 22. When the solenoid |1 is energized, the armature I9 isactuated toward the right (see Fig. 3), and the gyro wheel is thusdeclutched from the gyro motor GM.

The lever 20 is provided with an arm |06 for coaction with the gyrolocking means to prevent release of the rotating assembly before thegyro wheel is Vreleased from the motor.

The locking means for the rotating assembly comprises a generallyH-shaped member |08 pivoted to the frame 1| at the outer ends |09 and I8of the lower legs. The upper legs and ||2 are designed to straddle theouter gimbal ring 'l0 with a fairly close fit, so that this ring, whenmember |88 is in locking position, can not rotate about its trunnions inthe frame. Since the gimbal ring 18 can have a right and a wrongposition, it is important that it be made impossible to properlyposition member |08 except when the gimbal ring 19 is in the rightposition. To this end, we provide one quadrant of the ring With smallprojections, as H3, shown in Fig. 2, at each side of the ring. Theseprojections are, when ring 10 is in the wrong position, in the path ofthe upper legs of the member |88. Member |08 can thus be positionedcorrectly to lock ring 10 only when the proper quadrant of the ringfaces the upper legs of member |08.

The upper ends of the legs and ||2 are provided with projections and|I5. These projections carry bolts as shown. These bolts may be lockedin such position that the upper ends engage the bottom side of the portside of ring 60 when this ring is in proper position.

The wrong side of the ring 60 is provided with projections ||8 and ||1that are in the path of the upper ends of the bolts in the projections||l| and |5. Member |08, even if ring 1D be correctly positioned, cannot be moved to locking position except if both rings 60 and 10 are incorrect position.

Further, as long as member |08 is not in locking position, the arm |06will rest on the shou1 der ||8 and the gyro wheel 23 can not be driven.

The member |88 is normally biased to move out of locking engagement bythe tension spring |20 secured to member |08 and the frame. Theunlocking operation, once the member |08 is in locking position, can nottake place because arm |06 is then disposed in front of shoulder I8. Theonly way the rotary assembly can be unlocked is after the gyro wheel isup to speed and the torpedo has been red so as to energize the solenoid|1.

The gyro transfer switch comprises a threearmed member |2| pivoted on apivot transverse of the torpedo and biased by a suitable spring as shownto rotate clockwise. Such clockwise rotation can, however, not takeplace, except the member |08 be out of the locking position, because arm|22 rests on shoulder |23.

When in the position shown in Fig. 3, the gyro transfer switch is inposition to close contacts I4 in the circuit of both the gyro motor GMand solenoid |1.

After the torpedo is fired, the trigger switch energizes solenoid I1long enough to rapidly disengage the drive connection between the gyromotor and the gyro wheel. This time is more than ample to cause spring|20 to move the H-shaped member |08 toward the observer, as seen in Fig.3, or counterclockwise, as seen in Fig. 2, so as to unlock the rotatingsystem. y

The shoulder |23 thus 'moves out from under the arm |22 and inconsequence the circuit for the gyro motor and for the solenoid I'I isinterrupted at contacts I4. Contacts 28 are, however, closed, so thatthe circuit for the propulsion motor is closed.

At the same time that solenoid I`| is energized, the armature |9 causesarm |06 to move up or clockwise, so that shoulder H8 moves under the arm|06. The deenergization of solenoid l1 can thus have no further eiect onthe motion of clutch elements 61 and |00. These elements 61 and |00 arepositively held at a considerable distance from each other by arm |06and shoulder H8.

'I'he gyro wheel, therefore, assumes its function of controlling thesteering of the torpedo to the course set by the appropriate movement ofthe torpedo with reference to roller 32.

While we have shown but one embodiment of our invention, bothschematically and in detail, we do not wish to be limited to theparticular showing made, but wish to be limited only by the scope of theclaims hereto appended.

We claim as our invention:

l. In an automatic steering control for a submersible craft, incombination, a rotatable assembly comprising, a gimbal ring disposed toro tate about a vertical axis when the craft is operating on even keel,a second gimbal ring disposed to rotate on a horizontal axis at rightangles to the axisof rotation of the rst girnbal ring, a gyro wheeldisposed to rotate about a horizontal axis at right angles to both theother two axes of rotation mentioned; a frame for the rotatable assemblyfixed to the craft, means for locking the gimbal rings against rotation,said locking means comprising a generally H-shaped lever pivoted to theframe at two of its parallel legs so that the other two parallel legs,or free legs, may straddle the outer gimbal ring to prevent it fromrotating, means on the outer girnbal ring for preventing the free legsfrom straddling the outer gimbal ring except the outer gimbal ring be inthe correct position, means on the free legs adapted to engage the innergimbal ring to prevent it from rotating, means on the inner gimbal ringadapted to prevent locking engagement between free legs and the innergimbal ring except the inner gimbal ring be in correct position; a motorfor driving the gyro wheel; a clutch for coupling the gyro wheel to themotor; a clutch lever for actuating the clutch, said clutch lever havinga part disposed to engage the at side of the H-shaped lever to preventunlocking of the rotatable assembly when said H-shaped lever is inposition to lock the gimbal rings and when the clutch lever is inposition for the clutch to couple the motor to the gyro wheel anddisposed to engage the edge of the H-shaped lever when the H-shapedlever is not in locking position so that the clutch lever can not beactuated to engage the clutch once the rotatable assembly is unlocked.

2. In a steering control for a torpedo, in combination, a source ofelectric energy, a gyro motor adapted to be connected to the source ofenergy, a rotating assembly including a gyro wheel mounted to have, whenreleased, three degrees of "freedom of rotation, the gyro wheel mountedto have a horizontal spin axis and a vertical precession axis, a clutchcoupling the gyro wheel tothe gyro motor, locking means for locking therotating assembly so that the gyro wheel has but one degree of freedomof rotation namely about the spin axis, adjustable means disposed foradjustment axially of the spin axis for producing a precession about theprecession axis to compensate for the latitude at which the gyro wheelis used for controlling the torpedo, and means responsive to the ring ofthe torpedo for decoupling the gyro motor from the gyro wheel and forreleasing the locking means.

3. In an automatic steering control for a sub mersible craft, incombination, a gyrostat including a gyro wheel mounted, when released,to have three degrees of freedom of rotation and disposed on the craftso that the precession axis is vertical, locking means for holdingcertain of the elements of the gyrostat so that the gyro Wheel has butone degree of freedom oi rotation namely about the spin axis, drivingmeans for the gyro wheel, means responsive to the starting of the craftfor decoupling the gyro Wheel from the gyro motor and for operating saidlocking means to release the gyro wheel so that it has three degrees offreedom of rotation, means responsive to the position of the precessionaxis With reference to a selected point on the craft for controlling thesteering of the craft so that the precession axis holds a selectedposition with reference to the selected point on the craft, and meansresponsive to a selected distance of travel of the craft for causing the'craft to move in a spiral course.

4. In an automatic steering control for a submersible craft, incombination, a source of electrical energy, electromagnetic steeringcontrol devices, gyroscopic means for controlling the energization ofsaid electromagnetic devices as a function of the direction of travel ofthe craft with reference to a direction of travel of the craft selectedby said gyroscopic means, said gyroscopic means including a gyro wheel,a gyro motor, connected to the source of energy, for driving the gyrowheel, means for locking the gyro wheel in position to have one degreeof freedom of rotation about a horizontal spin axis, means responsive tothe starting of the craft for uncoupling the gyro Wheel from the gyromotor and for unlocking the gyro wheel so that it has three degrees offreedom of rotation, means responsive to the unlocking of the gyro wheelfor interrupting the electrical connection of the gyro motor and sourceof energy.

HENRY V. PU'IMAN.

MERRILL G. LEONARD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,173,435 Jones Feb, 29, 19161,153,678 Dieter Sept. 14, 1915 1,309,592 Tanner et al. July 8, 19191,421,854 Sperry July 4, 1922 FOREIGN PATENTS Number Country Date365,190 British Dec. 19, 1931

